I am very embarassed. I retried it in Windows and now the left front
sound is clearlly coming out the center speaker and the left speaker is
dead there too. A hardware problem! The left-front speaker sits on the
table right next to where the cats lie. The cats have chewed up the
cable - it was pretty flimsy to begin with. I am sorry to have bothered
you, but I am very grateful for your help. I don't think I would have
solved it so soon without your help.
Thank you very much,
Tom Corner